Question

for each of the noted items on the ph scale, match the label that indicates (roughly) how many times more acidic they are compared to water. 10 100 1,000 10,000 drag each item above to its appropriate location in the image. note that every item may not have a match, while some items may have more than one match. 8 - seawater (7.5 - 8.3) human blood (7.4) 7 - neutral - pure water milk (6.5) 6 - natural rainwater (5.6) 5 - tomatoes (4.5) 4 - oranges (3.5) 3 - lemons (2.3) 2 - stomach acid (1.5 - 2.0) 1

Explanation:

Step1: Recall pH - acidity relationship

The pH scale is logarithmic. Each unit decrease in pH represents a ten - fold increase in acidity.

Step2: Calculate acidity ratio for milk

Milk has a pH of 6.5 and water has a pH of 7. The difference in pH is \(7 - 6.5=0.5\). The acidity ratio is \(10^{0.5}=\sqrt{10}\approx 3.16\), so no match.

Step3: Calculate acidity ratio for natural rainwater

Natural rainwater has a pH of 5.6. The difference in pH from water (\(pH = 7\)) is \(7 - 5.6 = 1.4\). The acidity ratio is \(10^{1.4}\approx 25.12\), so no match.

Step4: Calculate acidity ratio for tomatoes

Tomatoes have a pH of 4.5. The difference in pH from water is \(7 - 4.5=2.5\). The acidity ratio is \(10^{2.5}=10^{2}\times10^{0.5}=100\times\sqrt{10}\approx 316\), so no match.

Step5: Calculate acidity ratio for oranges

Oranges have a pH of 3.5. The difference in pH from water is \(7 - 3.5 = 3.5\). The acidity ratio is \(10^{3.5}=10^{3}\times10^{0.5}=1000\times\sqrt{10}\approx 3162\), so no match.

Step6: Calculate acidity ratio for lemons

Lemons have a pH of 2.3. The difference in pH from water is \(7 - 2.3 = 4.7\). The acidity ratio is \(10^{4.7}=10^{4}\times10^{0.7}\approx10^{4}\times5.01\approx 50100\), so no match.

Step7: Calculate acidity ratio for stomach acid (using mid - value 1.75)

The mid - value of stomach acid pH range (\(1.5 - 2.0\)) is 1.75. The difference in pH from water is \(7 - 1.75 = 5.25\). The acidity ratio is \(10^{5.25}=10^{5}\times10^{0.25}\approx10^{5}\times1.78\approx178000\), so no match.

Since the question seems to expect approximate matches:
If we consider rough approximations:
For a pH difference of 1, the substance is 10 times more acidic. For a pH difference of 2, it is 100 times more acidic, for a pH difference of 3, it is 1000 times more acidic and for a pH difference of 4, it is 10000 times more acidic.
For a substance with pH = 6 compared to water (pH = 7), it is 10 times more acidic.
For a substance with pH = 5 compared to water (pH = 7), it is 100 times more acidic.
For a substance with pH = 4 compared to water (pH = 7), it is 1000 times more acidic.
For a substance with pH = 3 compared to water (pH = 7), it is 10000 times more acidic.

Answer:

• Milk (pH = 6.5, roughly close to pH = 6) is roughly 10 times more acidic than water.
• Natural rainwater (pH = 5.6, roughly close to pH = 6) is roughly 10 times more acidic than water.
• Tomatoes (pH = 4.5, roughly close to pH = 4) is roughly 1000 times more acidic than water.
• Oranges (pH = 3.5, roughly close to pH = 3) is roughly 10000 times more acidic than water.